CVE-2026-67599 ClearFoundation CVE debrief

Who should care

System administrators and security teams using ClearOS 7.9, especially those with internet-exposed systems or weak authentication mechanisms, should review and restrict access to the Log Viewer component, implement input validation and sanitization, and limit NOPASSWD sudo privileges for the webconfig user. System administrators and security teams should immediately review and restrict access to the Log Viewer component, implement input validation and

Why it matters

CVE-2026-67599 is a high-severity OS command injection vulnerability in ClearOS 7.9's Log Viewer component. Authenticated attackers can execute arbitrary commands, escalate to root, and potentially move laterally within the network. System administrators and security teams should immediately review and restrict access to the Log Viewer component, implement input validation and sanitization, and limit NOPASSWD sudo privileges for the webconfig user.

• Immediate escalation to root due to extensive NOPASSWD sudo privileges
• Potential for lateral movement within the network
• Possible data breaches or unauthorized access
• Required verification of system inventory and exposure

Technical summary

The vulnerability exists in the Log Viewer component of ClearOS 7.9. An authenticated attacker can execute arbitrary commands by submitting unsanitized input through the filter parameter, which is interpolated directly into a shell command in File.php. The webconfig user has extensive NOPASSWD sudo privileges by default, allowing for immediate escalation to root. This vulnerability has a high CVSS score of 8.6 and is classified as HIGH severity. The vulnerability allows immediate escalation to root due to extensive NOPASSWD sudo privileges granted to the webconfig user by default.

Defensive priority

High priority for systems using ClearOS 7.9, especially those exposed to the internet or with weak authentication.

Recommended defensive actions

• Immediately review and restrict access to the Log Viewer component
• Implement input validation and sanitization for the filter parameter
• Limit NOPASSWD sudo privileges for the webconfig user
• Monitor for suspicious activity and potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD entry provide details on the vulnerability. However, the exact scope of affected systems and versions requires further verification. The vulnerability exists in the Log Viewer component of ClearOS 7.9. An authenticated attacker can execute arbitrary commands by submitting unsanitized input through the filter parameter, which is interpolated directly into a shell command in File.php. The webconfig user has extensive NOPASSWD sudo privileges by default, allowing for immediate escalation to root. The CVE record was

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.